1. Field of the Invention
The present invention relates to a method for testing functions of constituting devices of a painting apparatus and an apparatus for the same.
2. Related Art
The conventional paint supply device is shown in FIG. 14. As shown in FIG. 14, the paint supply device B comprises an air cylinder device 101 for a pump connected to an air supply such as an external air compressor (not shown) and a pump device 102 for painting connected under the air cylinder device 101.
In particular, a cylindrical paint tank 104 of the pump device 102 is placed under the air cylinder device 101 over a support member 103. A cap 106 having an inlet valve 105 of a ball valve is screwed in the lower portion of the paint tank 104. An end of a valve rod 109 connected to a piston rod 108 of a piston 107 of the air cylinder device 101 is inserted into the upper portion of the paint tank 104. There screwed in the valve rod 109 a hooked cylindrical member 112 which has a paint exhaust hole 110 constituted by a central hole and a side hole which are communicated from the other at one end and which comprises a delivery valve 111 of a ball valve at the other end having a small diameter. A seal member 113 is placed around the hooked cylindrical member 112 so as to prevent the paint from leaking when the pump is operated.
As the air cylinder device 101 for pump is operated, the piston 107 is driven, and the valve rod 109 together with the piston rod 108 is moved vertically. Then, the paint in the external paint tank PT is sucked into the paint tank 104, and the paint in the paint tank 104 is supplied to the spray gun 116 through the paint exhaust hole 110, an upper room 104a of the paint tank 104, a pipe 114, and a regulator 115. It should be noted that in order to limit the vertical movement of the piston 107, a detecting rod 117 is connected to the upper portion of the piston 107 and an engaging part 118 is placed on the detecting rod 117, so that the position is detected by external limit switches 119, 120. The regulator 115 is communicated to an air supply 122 through a solenoid valve 121 for adjusting the pressure. Further, the spray gun 116 is communicated to the air supply 124 for trigger operating through a trigger solenoid valve 123.
However, with thus constructed paint supply device B, when the paint is supplied to the spray gun 116, if the seal property of the seal member 113 of the pump device 102 for pump is lowered, the slide resistance due to the valve rod 109 is decreased. Since the reciprocating motion per unit time of the valve rod 109 is increased to obtain the necessary reference pressure, the frequent pulsation of the paint due to the reciprocating motion of the valve rod 109 cannot be adjusted by the regulator 115. In result, the paint pattern is disordered. Further, this fasten the wear of the piston 107 which slides in the cylinder of the air cylinder device 101 and shortens the life time of the air cylinder device 101.
Further, when any of parts or devices in the painting apparatus is replaced by a new one after it reaches life period, the new part is assumed to work normally and placed in the painting apparatus without it is tested.
However, in practice, when the new part or device is placed in the painting apparatus, the replaced part or device frequently does not work normally. In the manufacturing line, if the operation of the devices and the painting condition are checked by eye or gauge, and the defective is found, it can be replaced by a new one again. However, the instant change of the gauge cannot be checked, which causes the defectives.